1. Field of the Invention
The present invention relates to a power supply device for generating a high voltage, and more particularly to such a power supply device utilizing a flyback transformer.
2. Description of the Prior Art
There are already known power supply devices utilizing a flyback transformer. In such known power supply devices the flyback transformer is driven, as shown in FIG. 1, by a power transistor-driving transformer 2 connected with an oscillator 1 and a power transistor 3 for activating a flyback transformer 4 for supplying a high voltage to a high-voltage circuit 5. In this manner the prior art requires a separate transformer 2 for driving the power transistor 3.
For this reason such known devices have been associated with drawbacks of:
a relatively high manufacturing cost due to the use of the transformer; and PA1 difficulty in realizing highly precise control due to the use of a transformer of a poor input-output linearity in comparison with that of the semiconductor element.